An integrated semiconductor chip includes a large number of electrical elements, such as transistors, capacitors, resistors and so on, and the electrical elements are connected with wirings of certain patterns to form functional circuits. The size of the integrated semiconductor chip becomes smaller and the functionality thereof becomes being magnified over several generations. However, there is an inherent limitation in reducing the size of the electrical elements. Thus, a multilevel interconnection technology of the electrical elements has been actively studied and developed. Thus, in order to manufacture the semiconductor device with the multilevel interconnection, the planarization process of metal film should be carried out. Generally it is not easy to polish the metal film because of the metal film having high strength, therefore for effectively polishing the metal film, the metal film is transformed to metal oxide which has relatively low strength and then is polished. In the process of polishing the metal film, it is necessary to suppress damage (scratch occurs, etc.) to an insulating film such as a silicon oxide film.
WO 2007-029465 discloses a polishing compound, a method for polishing surface to be polished and a process for producing semiconductor integrated circuit. The polishing compound comprises abrasive grains, one or more polishing rate controlling agents such as benzotriazoles, an organic solvent having a relative dielectric constant of 15-80, a boiling point of 60-250° C., and a viscosity of 0.5-60 mPa·s at 25° C., and water. In the above-mentioned reference, the pH of slurry is different from that in the present invention and mixture of at least two organic solvents is used. Korean Unexamined Publication No. 10-2012-124395 discloses an aqueous electrolyte solution containing citric acid and ammonium hydrogen fluoride. in the above Korean reference, a method for removing the metal surface, an used catalyst, an oxidizer and a dispersing agent are different, and the metal film is removed by etching with an electrolytic solution not polishing. Japanese Unexamined Publication No. 2000-254867 discloses a polishing sheet containing a mixing solvent consisting of at least two components, wherein the boiling point of each component is different to each other. The Japanese Unexamined Publication No. 2000-254867 is different from the present invention in view of the intended purpose and kinds of solvent used, is silent to amount of solvent and is related but to the polishing sheet not slurry composition.